![Page 1: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/1.jpg)
Hormonal Regulation of the Reproductive
System
![Page 2: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/2.jpg)
1. Primary sex characteristics (gonads and sperm) are produced while the fetus is still in utero (testes descend into scrotum at third month of development).
2. Secondary sex characteristics (body/facial hair, growth of larynx, muscle strengthening) occur at puberty due to hormonal changes.
Hormonal Control
![Page 3: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/3.jpg)
Hormonal Control At Puberty
1. Hypothalamus• Releases gonadotropic releasing hormone (GnRH)• First released at puberty. • GnRH causes the Pituitary to release:
2. Pituitary• Follicle Stimulating Hormone (FSH) – Stimulates sperm
production in seminiferous tubules.• Lutenizing Hormone (LH) – promotes testosterone production
(which then promotes sperm production).
![Page 4: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/4.jpg)
Hormonal Control At Puberty
Interstitial Cells• Interstitial cells in testes produce testosterone
when stimulated by LH. • Testosterone stimulates spermatogenesis and
development of secondary sex characteristics.
![Page 5: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/5.jpg)
Testosterone & Sperm Production are Controlled by Negative Feedback
• Testosterone deactivates the hypothalamus, inhibiting the production of LH by the pituitary.
• Sertoli cells inhibit the hypothalamus from secreting GnRH and the pituitary from secreting FSH.
![Page 6: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/6.jpg)
Interesting Facts Castratis – Male sopranos popular in 17 and 18
Centuries
Prostate cancer is one of the most common cancers in males. (In Canada, 81 Canadian men die from prostate cancer every week). It is detected via blood tests for PSA or through the digital rectal exam. Men over the age of 50 should be examined yearly.
![Page 7: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/7.jpg)
Menstrual Cycle
![Page 8: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/8.jpg)
Puberty in Females Begins when GnRH
levels increase
Recognized with first episode of menstrual bleeding
![Page 9: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/9.jpg)
Menstrual Cycle Facts About 28 days long Phases
◦ Flow phase◦ Follicular phase◦ Ovulation event◦ Leuteal phase
Amenorrhea: Absence of a menstrual cycle Menopause: Cessation of menstrual cycles
![Page 10: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/10.jpg)
Ovarian cells involved primary oocyte
◦ becomes ovum for fertilization
granulose or follicle cells◦ provide nourishment
ovaries undergo continual decline after onset of puberty
500+ follicles start to develop during every cycle, but only a single follicle becomes dominant & reaches maturity.
![Page 11: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/11.jpg)
Oogenesis Overview
![Page 12: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/12.jpg)
Maturation of Follicle and Oocyte
![Page 13: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/13.jpg)
Controlled by Hormones Hypothalamus
◦ gonadotropin-releasing hormone (GnRH) targets pituitary.
Pituitary◦ FSH starts egg
maturation.◦ LH triggers ovulation,
and formation of corpus luteum.
Ovary◦Granulose cells
Estrogen promotes thickening of endometrium.
◦Corpus luteum estrogen and
progesterone maintains lining.
![Page 14: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/14.jpg)
Cycle SummaryFlow Follicular Ovulation (event) Luteal
shedding of endometrial lining
Day 1 – 5
NO HORMONES
development of follicles within ovaryestrogen triggers thickening of endometrium
Day 6 – 13
High FSH, then estrogen, ends with LH spike.
Oocyte (egg) bursts from ovaryfollicle cells become corpus luteum
Day 14
Highest LH Point
corpus luteum secretes estrogen and progesteronemaintains lining, inhibits ovulation
Day 15 – 28
High progesterone and estrogen
![Page 15: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/15.jpg)
Cycle and Cells
![Page 16: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/16.jpg)
Surgical Birth Control
Tubal Ligation
![Page 17: Hormonal Regulation of the Reproductive System](https://reader036.vdocuments.site/reader036/viewer/2022062310/56815f78550346895dce7f62/html5/thumbnails/17.jpg)
Procedure fallopian tubes are
cut, burned, or blocked with rings, bands or clips.
now under local anaesthesia.